Arduino IDE 1.0.5 + UNO + Adafruit 1.8" TFT Shield / drawFastVline x 8 x 10000, then hang

TFT_debug.ino

/*
  TFT demo
  https://github.com/arduino/TFT
  http://arduino.cc/en/Reference/TFTLibrary
*/

// randomdot

#include <TFT.h>
#include <SPI.h>

#define TFT_CS  10
#define TFT_DC   8
#define TFT_RST  NULL
#define TFT_SCLK  13
#define TFT_MOSI  11
#define SD_CS  4

Adafruit_ST7735 screen = TFT(TFT_CS, TFT_DC, TFT_RST);  // for UNO
/// TFT screen = TFT(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);  // for Leonardo

void setup(void) {
    Serial.begin(9600);
    while(!Serial);
    Serial.println("START");

  SPI.setClockDivider(SPI_CLOCK_DIV4);  // SPI speed

  screen.initR(INITR_BLACKTAB);
  screen.setRotation(3);
  screen.fillScreen(ST7735_BLACK);

// screen.begin();
//  screen.background(0,0,0);
//  screen.fill(255,255,255);
    
}

const int XMAX=ST7735_TFTHEIGHT;
const int YMAX=ST7735_TFTWIDTH;

unsigned long counter=0;

void loop() {
  int x1,y1,x2,y2,c,t;
  unsigned long stime,etime;
  
  stime=millis();
    c=random(65536);
  for(int i=1;i<=10000;i++) {
    x1=random(0,XMAX);
    y1=random(0,YMAX);
    x2=random(0,XMAX);
    y2=random(0,YMAX);
    t=abs(y1-y2);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
    screen.drawFastVLine(x1,y1,t,c);
  }
  etime=millis();
  counter++;
  Serial.println(counter);
}